Cell adhesion is important in developmental events and in tumor spread. The nature of the mechanisms of intercellular adhesion is not well understood. Over the past decade we have contributed to an understanding of this problem by identifying glutamine requiring pathways involved in cell adhesion and by demonstrating that specific carbohydrate groups at the cell surface appear to play a role in the adhesion mechanism. This project extends our studies by: (1) examining the role of specific tumor cell populations in production and binding of teratoma adhesion factor; (2) beginning to characterize teratoma adhesion factor; (3) isolation of teratoma adhesion factor cell surface receptor sites; (4) identification of terminal carbohydrates involved in cultured teratoma cell adhesion. We hope that our multi-faceted approach to the problem of cell adhesion will result in a better understanding of the molecular basis for adhesion and of the reasons for the altered adhesiveness of malignant tumor cells.